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<head><meta charset="utf-8"><title>Feature index in book · wg-traits · Zulip Chat Archive</title></head>
<h2>Stream: <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/index.html">wg-traits</a></h2>
<h3>Topic: <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/Feature.20index.20in.20book.html">Feature index in book</a></h3>

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<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/Feature%20index%20in%20book/near/209318847" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> detrumi <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/Feature.20index.20in.20book.html#209318847">(Sep 07 2020 at 18:23)</a>:</h4>
<p>So, with all the talk about foreign types and such, it takes some effort to track down documentation for that rust feature. I had to:</p>
<ul>
<li>Find the <a href="https://github.com/rust-lang/chalk/issues/595">original chalk issue</a>,</li>
<li>look at the code example (luckily there was one) and notice that it uses <code>#![feature(extern_types)]</code>...</li>
<li>Look that up in the <a href="https://doc.rust-lang.org/unstable-book/language-features/extern-types.html">Rust Unstable Book</a>...</li>
<li>which links to the <a href="https://github.com/rust-lang/rust/issues/43467">tracking issue</a></li>
<li>which links to the <a href="https://github.com/rust-lang/rfcs/blob/master/text/1861-extern-types.md">RFC</a> and PR that implements it</li>
</ul>
<p>Would it be an idea to have an index of rust features that are relevant to chalk in the chalk book, with code examples?  Of course the unstable book (sometimes) has a description, but that includes a lot of features that aren't relevant to trait solving.</p>



<a name="209319011"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/Feature%20index%20in%20book/near/209319011" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> detrumi <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/Feature.20index.20in.20book.html#209319011">(Sep 07 2020 at 18:26)</a>:</h4>
<p>While working on chalk I often have to look up rust features that I'm not yet familiar with, and I imagine I'm not the only one</p>



<a name="209332002"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/Feature%20index%20in%20book/near/209332002" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jubilee <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/Feature.20index.20in.20book.html#209332002">(Sep 07 2020 at 22:46)</a>:</h4>
<p>Yes.</p>



<a name="209436595"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/Feature%20index%20in%20book/near/209436595" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/Feature.20index.20in.20book.html#209436595">(Sep 08 2020 at 20:02)</a>:</h4>
<p>that sounds useful!</p>



<hr><p>Last updated: Aug 07 2021 at 22:04 UTC</p>
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